After waking at the house of Henry Sturgess after being rescued, and while walking down the stairs you see through the windows window-blinds, which were invented in 1888, Lincoln died in 1865.
Admittedly, I haven't seen the movie so am not sure if you are referring specifically to Venetian blinds (the most commonly referred to "window blinds" comprised of a series of horizontal slats). If so, then you are quite wrong about their history. Venetian-style blinds were used in both Egypt and east Asia thousands of years ago. It's believed they were first invented in ancient Persia. Even if you want to limit it to more modern times, the first Venetian blinds were patented in England in 1760. That's 100 years before the events of the movie.